Synchronous trigger control



Sept. 14, 1943.

c. G. TRIMBACH SYNGHRONOUS TRIGGER CONTROL Filed Nov. 16. 1940 INVENTORCLE-M Gimme/am.

0 ATTORNEY Patented Sept. 14, 1943 UNITED STATES 2,329,668 SYNCHRONOUSTRIGGER CONTROL Clem G. Trimbach, Eggertsville, N. Y., asslgnor toCurtiss-Wright Corporation, a corporation Delaware Application November16, 1940, Serial No.365,9'l0

8 Claims.

This invention relates to guns and firing mechanisms therefor and inparticular provides a trigger system by which a plurality of guns may befired simultaneously.

Although the invention may be used in other environments, it isparticularly adapted for use with flexibly mounted machine guns inaircraft. Where one or more guns are carried for joint movement on aflexible gun mount, and where they are movable about the flexible gunmount traverse pivot, it is desirable to so arrange the firingmechanisms that the guns will fire simultaneously so that yawing momentsdue to gun recoil will be balanced on the traverse pivot. Wheresynchronous fire is not assured, vibrator couples will be imposed on theguns and mounting therefor making it diflicult for a gunner to hold themultiple guns on an aiming point.

An object of the invention is to provide a tri ger mechanism to firemultiple guns simultaneously and further, to provide a mechanism whichshall prevent the firing of one gun which may be in battery untilanother gun of the system which may be out of battery returns to itsbattery posi-.

tion. Where the rate of fire of an individual machine gun may be in theneighborhood or 800 rounds per minute, the operating cycle of the gun isobviously very short. If two guns of nearly similar firing rate areallowed to fire without synchronous control, lateral vibratory couplesare set up which make gun aiming difllcult and indeterminate. If one gunis slightly slower in its rate of fire than another gun, the presentinvention provides means of controlling the rate of fire of the fastergun to that of the slower gun.

A mrther object of the invention is to provide a synchronous triggermechanism which maybe applied to two or more guns whether they beflexibly mounted or not.

Further objects or the invention will become 40 apparent in reading thesun-joined detailed description in connection with the drawing, in

I which:

1 is a .plan view of a pair of machine guns flexibly mounted andincorporating the previsions of the invention;

Fig. 2 is a side elevation comprising a section on the line 2-2 of Fig.1;

Fig. 3 is a section on the line 3--3 of Fig. 1;

and

Fig. 4 is an enlarged detailed plan view of a portion of the mechanismof Fig. 1.

In Figs. 1 and 2, a lateral beam ill comprises the support for aflexible gun mount which includes a vertical trunnion I l engaged in asuitable socket in the beam l0 and carrying a cross piece l2 from whichadapter plates l4, l5, l6, and ll extendupwardly and rearwardly inparallel rela- I mode of mounting the gun on its plates i6 and I1applies with equal force to the mounting of the gun IS on its plates 14and I5. At the upper rearward ends of the plates is and I! are 15 alinedholes'engaged by pins 22 each of which engages a bracket 23 secured tothe front end of a recoil assembly 24, the latter comprising cylindersat its forward end engaged by pistons 25 whose forward ends are joinedby a mounting 20 bolt 23 engaging a collar 21 embracing a portion of thegun 20 to form a forward point of support therefor. The unit 24 isrearwardly extended as at 29 and 30, the rearward ends of the members 29and 30, which lie parallel to one another,

2 being joined to one another by a cross member 32 on which are mountedaiming handles 33. Toward the rearward end of each member 29 and is aplate 34 having a longitudinally extend- -ing slot 35 engaged by aguiding and mounting an lug 36 forming a part of the gun 20. Thus, the

gun 20 is mounted'at two positions by the elements 26 and 36 and isreciprocable in a foreand-aft direction on the gun cradle comprised bythe members 29 and 30. This reciprocation 35 is of course induced byrecoil due to gun firing and leaves the cradle and gun aiming handles 33free of recoil induced vibrative movement.

Eachmemberand 30 is providewwith depending struts 33 which convergetoward one another and are clevised to one end of a piston-cylindersystem 40,.pivoted at its other end to the cross piece l2. This unit 40contains a. balance spring strong enough to balance the cradle and gunin diflerentpositions of elevation. The two parallel gun cradles aresecured together by the cross member 32.

The guns l9 and 20 are similar in all respects except that the breechend of each has a trigger mechanism 42 on its inner face-that is, theface adjacent to the other gun. In the particular arrangement shown, thetrigger mechanism 42 as shown in Fig. 4 comprises a laterallyreciprocable trigger element 43 carrying a roller II. when the element43 is moved toward the sun,

the gun is fired and when said element moves away from its gun, the gunis locked against firing. To synchronize firing of the guns, a plate 46is disposed therebetween, this plate carrying, at its lateral edges, camfaces 41 which are engageable with associated trigger element rollers44. The distance between the opposed cam faces 41, toward the rearwardend of the plate 46, is such that the plate 46 may lie centrally betweenthe trigger mechanisms 42 without depressing either trigger element 43.The distance between the cam faces 41 at the forward end of the plate 46is such that, when the trigger mechanisms 42 lie opposite one another,the cam faces 41 engage both trigger rollers 44 and depress the triggerelements 43 to fire both guns simultaneously. At its rearward end, theplate 46 is pivoted as at 49 to a rod 50 for free lateral movement withrespect to the arm. The rod 50 in turn is clevised at 5| to a lever 52secured to a cross shaft 53 pivoted at its ends to the tops of thehandles 33. One end of the shaft 53 carries a trigger handle 54 whichmay be depressed by the gunner while he is grasping the handle withwhich the trigger handle 54 is associated.

It is obvious that when the handle 54 is released, the plate 46 movesforwardly under the influence of a suitable spring, not shown, underwhich condition both trigger elements 43 of the guns move into anon-firing position. When the trigger handle 54 is depressed, the plate46 is moved rearwardly, camming both trigger elements 43 toward theirguns to initiate firing thereof. As both guns fire, they move rearwardlyin recoil with respect to their cradles. If one gun, for instance thegun I 9, moves forward into battery before the gun 20, the triggerelement 43 of the gun l9 will move the plate 46 about its pivot 49toward the left and the gun l9 will not be fired at that instant. Sosoon as the gun moves forward into battery position, its trigger element43 will engage the cooperating cam face 41 shifting it back to a neutralposition. By the time the gun 20 reaches full battery position, bothtrigger elements 43 will be depressed to cause simultaneous firing ofboth guns.

From the above, it should be clear that so long as the trigger handle 54is held down, and presuming the guns l9 and 20 are full automatic guns,both guns will continue to fire at exactly the same rate, such ratebeing governed by the slower acting gun. It may be assumed that therecoil force of the guns is substantially the same and, since they arefiring simultaneously, the moment of one gun about the traverse pivot IIwill be balanced by the moment of the other gun about said pivot wherebythere will be no yawing tendency, either vibratory or otherwise, aboutsaid traverse pivot. Fig. 3 shows how the plate 46 is mounted betweenthe guns for longitudinal movement controlled by the trigger handle 54and for lateral movement controlled by the recoil position of the guns.The innermost plates 34 on the cradles are extended upwardly as at 56and are bent inwardly at their upper ends to form tracks or guideways 51for the plate 46 which is suitably slotted as shown to engage thetracks. The slots in the plate 46 are sufliciently deep to allow of thenecessary lateral movement of the 'plate as above described.

The dotted elements at 60 and GI indicate ammunition boxes and caseretrieving boxes for the guns.

Although in the showing, the guns are indicated as being bodilyreciprocable in recoil, it is within the scope of the invention toutilize guns which are rigidly mounted upon their adapters and tocoordinate the synchronizing mechanism with such portions of the gunactions as may reciprocate during gun operation, as for instance, thecharging handles. That is, the charging handles might engage the plate46 which plate by suitable extensions or fittings thereon, would actuatethe gun triggers when both guns are in battery position. It is alsowholly within the scope of the invention to utilize a member having thefunction of the plate 46 to operate trigger elements of respective gunswhich have different locations or directions of movement with respect totheir guns than the trigger elements 43 shown in the drawing.

' While I have described my invention in detail in its present preferredembodiment, it will be obvious to those skilled in the art, afterunderstanding my invention, that various changes and modifications maybe made therein without departing from the spirit or scope thereof.Iaim' in the appended claims to cover all such modifications andchanges.

I claim as my invention:

1. In a fiexible gun mount, a cradle pivoted for free traverse, machineguns in side-by-side relation on opposite sides of the traverse pivot,means mounting said guns for axial and independent reciprocation inrecoil, a common trigger actuator for operating the guns jointly, andmeans between the trigger actuator and the guns to effect simultaneousfiring of both guns to assure balanced recoil moments on said cradle toprevent the guns from yawing on said traverse pivot.

2. In a mount for twin machine guns in parallel relation, each gunhaving a trigger element on the breech side facing the other gun, alaterally swingable member between the guns having 0!!- posed camsurfaces engageable with respective trigger elements, and means to movesaid member in a forward and rearward direction to either actuate theguns or to cause them to cease firing.

3. In a mount for twin machine guns in parallel relation, each gunhaving a trigger element on the breech side facing the other un. alaterally swingable member between the guns hav ing opposed cam surfacesengageable with respective trigger elements, and means to move saidmember in a forward and rearward direction to either actuate the guns orto cause them to cease firing, said cam surfaces being so spaced apartthat, when the member is in firing position, both guns must be in fullbattery position before either of said trigger elements are actuated.

4. In a mount for twin machine gims mounted for independentreciprocation in recoil relative to the mount, a trigger element on eachgun movable therewith and relative thereto, a trigger actuatorcontrollably movable on the mount, and a trigger element engager movablewith the actuator and articulated thereto, said engager, when theactuator is controllably moved to firing position, having actuatingengagement with said trigger elements only when both guns are in fullbattery position.

5. In a gun mount comprising spaced substantially parallel g1ms havingfacing portions independently longitudinally movable from batteryposition from each of which projects a laterally movable triggerelement, a member having a face along each lateral edge engageable withone said element, the distance betweensaid faces being substantially thesame as the distance between said elements when both are depressed, and

means to articulate said member for free lateral movement whereby, whenone gunportion with its trigger element is longitudinally displaced frombattery position and from face contact, said member is freely movablelaterally to disengage the other trigger element,

6. In a gun mount comprising spaced substantially parallel guns havingfacing portions independently longitudinally movable from batteryposition from each of which projects a laterally movable triggerelement, a member having a face along each lateral edge engageable withone said element, the distance between said faces being substantiallythe same as the distance between said elements when both are depressed,means to articulate said member for free lateral movement whereby, whenone gun portion with its trigger element is longitudinally displacedfrom battery position and from face contact, said member is freelymovable laterally to disengage the other trigger element, and means tomove said member longitudinally to clear both trigger elements.

7. In a gun mount comprising spaced substanticulately mounted member toa position out of j tially parallel guns having portions independently25 longitudinally movable from battery position.

from each of which projects a movable trigger element, an articulatelymounted member having spaced faces contactable with respective elements,said "spaced faces being located on the mount to operatively contact'and move both trigger elements when both guns are in battery position,and also to articulate to non-operatively contact bothelements wheneither gun is out of its battery position.

8. In a gun mount comprising spaced substantially parallel guns havingportions independently longitudinally movable from battery position,from each of which projects a movable trigger element, an articulatelymounted member having spaced faces contactable with respectiveelements', said spaced faces being located on the mount to operativelycontact and move both trigger elements when both guns are in batteryposition, and also to articulate to non-operatively contact bothelements when either gun is out of its battery position, and means tomove said airoperating contact with both trigger elements when both gunsare in battery position.

CLEM G. 'I'RINIBACH.

